#pragma once
#include "header.h"
#include "lib.h"

// https://github.com/B-Con/crypto-algorithms
/*********************************************************************
* Filename:   sha256.h
* Author:     Brad Conte (brad AT bradconte.com)
* Copyright:
* Disclaimer: This code is presented "as is" without any guarantees.
* Details:    Defines the API for the corresponding SHA1 implementation.
*********************************************************************/


/****************************** MACROS ******************************/
#define SHA256_BLOCK_SIZE 32            // SHA256 outputs a 32 byte digest

/**************************** DATA TYPES ****************************/
typedef unsigned char BYTE;             // 8-bit byte
typedef unsigned int  WORD;             // 32-bit word, change to "long" for 16-bit machines

typedef struct {
	BYTE data[64];
	WORD datalen;
	unsigned long long bitlen;
	WORD state[8];
} SHA256_CTX;

/*********************** FUNCTION DECLARATIONS **********************/
void sha256_init(SHA256_CTX *ctx);
void sha256_update(SHA256_CTX *ctx, const BYTE data[], size_t len);
void sha256_final(SHA256_CTX *ctx, BYTE hash[]);

/**
 * @brief 对长度为text_len的text计算sha256并将结果保存在buf中
*/
void sha256_hash(unsigned char* buf, unsigned char* text, size_t text_len);

/**
 * @brief 对长度为text_len的text进行sha256哈希并与标准值对比，若二者
 * 相等则返回1，否则返回0
*/
int sha256_verify(unsigned char* standard_hash, unsigned char* text, size_t text_len);

